1. Institute for Health Economics and Clinical Epidemiology (IGKE); Cologne University Hospital; Cologne Germany
2. Institute for Health Services Research and Health Economics; Heinrich Heine University; Duesseldorf Germany
3. Department of Psychiatry and Psychotherapy and Geriatric Centre; Tuebingen University Hospital; Tuebingen Germany
4. Department of Medicine and Health Services Research, BARMER Statutory Health Insurance Fund (former BARMER GEK); Wuppertal Germany
5. Helmholtz Zentrum Muenchen; Institute of Health Economics and Health Care Management; Neuherberg Germany